Circuit-breaker.



H. G. MAODONALD. 011101111" BREAKER.

APPLICATION FILED JUNE 8, 1908.

' 1,087,500. Patented Feb. 17,1914.

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a I? IN VENTOR V y 3 ATTGRN EY H. G. MAODONALD.

CIRCUIT BREAKER.

APPLICATION FILED JUNE 8, 1908.

1,087,500; Patented Feb. 17,1914.

3 SHEETS-SHEET 2.

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2 BY I ATTORNEY WITNESSES:

H. G. MAODONALD. CIRCUIT B BEAKER. APPLIGATIONTILED JUNE s, 1908.

Patented Feb. 17, 1914.

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INVENTOR M41, mmwL nniTEn-sTATEs PATENT OFFICE.

HOWARD G. MACDONALD, OF IPITTSBURGH, PENNSYLVANIA, ASSIGNOR, BY MESNE AS SIGNMENTS, TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, 01' EAST PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

CIRCUIT-BREAKER.

To all whom it may concern Be it known that I, HOWARD G.. Mao- DONALD, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented anew and useful Improvement in Circuit-Breakers, of which the following is v a specification.

members in closed position under conditions which would normally renderthe automatic release member active.

' The operating mechanism of my circuitbreaker comprises, in general, a toggle joint formed by suitable levers and links by which the movable contact members may be brought into engagement with the stationary members butwhich may be released in either direction. I

Figure l of the accompanying drawings is an elevation of a circuit interrupter con structed in accordance with my 1nvent1on,

the inclosing casing being in section to disclose the operating mechanism. 2 is a plan view of the mechanism shown in Fig. 1; Figs. 3 and 1 are views showing the relation of-parts of the operating mechanism .when the interrupter occupies the one or the other of its open-circuit positions, and Fig. is a detail view of the release mechanism. Figs. 6 and 7 are, respectively, an elevation, and a plan view of a structurally modified operating mechanism which may be substituted for that shown the other figures.

Referring to Figs. 1 to 5, inclusive, of the drawings, the device-here illustrated comprises a plurality of stationary contact mem-' here 1, movable contact'members 2 to cooperate therewith, a handle lever 8, an op erating mechanism for the movable contact a release mechanism and electromembers, 1

T ie

responsive actuating means therefor.

parts of the interrupter are all supported by an intermediate portion 4 of the 'casing whichcom rises, in addition to this part, a cover 5 an an oil-containing tank 6; The stationary contact members 1 are secured to an insulating plate 7 which lies In a hOIl- Specification of Letters Pa tent.

Application filed June 8. 1908.

Patented Feb. 17, 1914.

Serial No. 437,345.

zontal plane andis secured to projections 8 on the body ofthe casing. The movable contact members 2 are resiliently secured to an insulating bar 9 and are connected to stationary terminals 10 on the insulating plate 7 by means of flexible conducting shunts 11. The insulating bar 9 is suspended from one end of a bell crank lever 12 by links 14,

' the said lever being rotatably mounted on a stationary shaft 13. The other end of the bell crank lever 12 is connected to a relatively stationary shaft 15 by means of a pair of links 16 and 17 which form a toggle joint. An actuating block 18 is operatively connected to the handle lever 3 and is adapt ed to close the circuit interrupter by forcing the links into a substantially straight line.

The release mechanism comprises a bell crank lever 19 having rollers 20 and 21 mounted on the respective ends of its arms, and lever arms 22 and 23 which are keyed to a shaft 2 1 on which the bell crank lever 19 is fulcrumed, the arm 22 being provided with a projection 25 against whichone arm of the bell crank lever 19 is held, under nor mal conditions, by means of a spring 26;

A well known form of electro-magnet 27 constitutes the electro-responsive means by which the release mechanism is operated,

two of these magnets being employed in the device illustrated. Each magnetcomprises a movable core member 28 to which a striker or hammer rod 29 is scoured, adjustable means for varying the air-gap between the stationary and movable core members,

and a coil for energizing these members.

The operation of the device is as follows:

Assuming'that the interrupter is closed and that the parts of the operating mechanism occupy the positions shown in Fig. 1; the circuit may'be automatically interruptedby energizing the electroanagnets. When eneg; gized, the movable core members, of these magnets are attracted toward the stationary core members and t-hejhammer rods strike the arms 22 and 23 and move them, together with the bell crank leverl9, in a clockwise directiomin opposition to the spring 26 .until s the roller 20 reaches a position whichwill permit the toggle links 16 and 17 to operate under the action of the weight imposed by the parts 14, 9 and 2 and move the parts 3, 1 8 and 19 to the positionsshown in Fig. 3. The interrupter 1s closed, when the parts are as indicated in Fig. 3,-by depressing the handle lever 3, since the projection 31 of the block 18 engages a pin 32 which connects the links 16 and 17 together and projects laterally therefrom. If the electro-magnet is .sufiiciently energized when the contact members are brought together in again closing the breaker, the shoulder 30 of the block 18 will. not engage the roller 21 when the handle lever 3 is moved downwardly from the position shown in Fig. 3, and, consequently, the toggle links will continue their movement to substantially the positions shown in Fig. 4 and the contact members will therefore remain in engagement-for only a short period of time. It is possible to close the interrupter when the parts are arranged as shown in Fig. 4 by. moving the handle lever 3 upwardly, since a shoulder 33 of the block 18 will engage the pin 32 and move the links 16 and 17 to substantially the positions indicated in Fig. 1. Again assuming that the circuit interrupter is closed, the

parts being arranged as shown in Fig. 1; if

it is desired to manually open the interrupter, the handle lever 3 may be raised, thereby causing a rotative movement of the bell crank lever19 by reason of the engagement of a projection 31 of the block 18 with the roller 21 and a consequent removal of the roller 20 from its locking engagement with the link 17..

Referring to Figs. 6 and 7, in which like parts are designated by the same reference characters, a latch 34 having a notch 35 near its end is substituted for the bell crank lever 19 and the block 18 is replaced by a lever 36,'an arm 37 of which is provided with a roller to engage the notch 35. The latch 34 is resiliently held against the projection 25 of the arm 22 and will be moved. out of its engagement with the roller of the arm 3:? by the hammer rod 29 when the electro-magnet is energized.

It will be understoodv that various structural modifications may be effected within 7 the scope of my invention, and, consequently, ,I desire that only such limitations shall be imposed as are specified in the appended claims.

I claim as my invention:

1. In a circuit-breaker, the combination with stationary and movable contact members, anoperating lever, a handle lever, a shaft to which the handle lever is secured and toggle links interposed between said operating lever and said shaft, of means operated by said handle lever to operat-ively engage either side of the pivot pin which connects said toggle links together to close the breaker. 4

2. In a circuit interrupter, the combina tion with stationary and movable contact members, an operating -lever and a handle lever, of. anoperativeconnection between the handle lever and the operating lever comprising toggle links and an operating block having lost-motion with reference to said links and having rejections to respectively engage the toggle oint at opposite sides.

3. In a circuit interrupter, the combine-- 4. In a circuit-breaker, thecombination with stationary and movable cOntact members and means for holding the members 1n engagement, of an operating mechanism comprising toggle links, manually operated means for moving said links in either direction into approximate alinement to effect engagement of said contact members and for releasing said links, and electromagnetic means for releasing said links.

5. In a circuit interrupter, the combination with stationary and movable contact members, an operating bell crank lever, a handle lever having an operating block and a pair of toggle links interposed between .the bell crank lever and the handle lever and adapted to be operated in either direct-ion by said operating block, of a movable stop for engaging one of the toggle links to hold the contact members in engagement, and electro-rev sponsive means for automatically displacing the stop under predetermined conditions.

6.- In a circuit interrupter, the combination with stationary and movable contact members, two substantially parallel shafts, an operating bell crank lever and a handle lever mounted upon the respective shafts, a pair ofv toggle links interposed between the operating lever and the handle lever, an operating block rigidly mounted on the handle lever shaft and having projections to engage the respective sides of the pivot which connects the toggle links together, of means for so acting upon one of the links as to hold the contact members in engagement and electro-responsive means for preventing a continued engagement of the contact members under predetermined conditions.

7. In a circuit interrupter, the combination with stationary and movable contact members, of an operating mechanism comprising toggle links'which maybe moved in either direction from a position of approximate alinement to separate the contact members, a stop for normallypreventing movement of the toggle links in one direction to separate the contact members, and a handle lever having means for engaging said links to move them into locking position from either. side I upon the respective shafts,

of their position'or" alinement.

nected toggle links interposed between the S. Ina circuit interrupter, the combination 1 handle lever and the-operating lever, and

with stationary and movable contact members, of an operating mechanism comprising toggle links Which may be moved in either direction from approximat alinement to separate the contact members, a sto serving to hold the toggle links in unsta 1e equilibrium for preventing movement thereof in one direction to separate the contact members, means dependent upon predetermined conditionsfor Withdrawing the stop, and a handle lever having means for moving the stop from its holding position.

9. In a circuit interrupter, the combination I 'With stationary and movable contact members, two substantially parallel shafts, an operating lever and a handle lever mounted means projecting engage either side of the pivot pin which connects said toggle links, of a movable stop for engaging one of said toggle links to prevent the separation of the contact members, and an electro-responsive release mechanism for displacing the stop under predetermined conditions.

In testimony whereof, I have hereunto subscribed my name this 29th day of May, 1908. v

HOWARD e. MAoj)ONALD. Witnesses:

J. on VALLE Amzrn,

BIRNEY HINES.

Copies of this patent may be obtained for five cents each, .by addressing the Commissioner of Patents,

walhlngton, D. 0."

two pivotally conom the handle lever to, 

